“…Further research is needed to investigate relationship quality as a potential mediating factor affecting the relation between training condition and cognitive outcome. Prior collaborative research suggests complex relationships between cognitive outcomes and both the nature of the partners' relationship (e.g., partner familiarity: Dixon, et al, 1997, Gould, et al, 1991, Gould, et al, 1994, Margrett & Marsiske, 2004partner gender: Margrett & Marsiske, 2002) as well as the collaborative interaction (e.g., Gould, et al, 1991, Gould, et al, 1994Kimbler, 2004). As noted by Carstensen, Levenson, and Gottman (1995) and Dixon and Gould (1996), the "expertise" developed in long-term relationships may facilitate the process and product of cognitive collaboration.…”